... not inclined to believe that a person with good common sense and average shooting skills is somehow helpless ...

With all genuine respect due ... A mouse is not helpless against a cat either, but any rational person will be hard pressed to explain why the latter won't be the victor on the basis of anything but blind chance. The battle doesn't always go to the strong, nor the race to the swift ... but we generally have an expectation in that regard as well.

I can't think of any field of endeavor where "average" is anything but a shade above incompetent. I've been a victim of violent crime on 4 occasions, 2 with guns pointed at me. I'll bet my continued survival on a more robust sense of reality.